Abstract: Mechanical and electronic properties of different SnO2 crystal structures were studied by density functional theory. For the exchange-correction energy we employed the generalized gradient approximation (GGA) in the PBE (Perdew, Burke and Ernzerhof) form. The lattice constants, bulk modulus and Young’s modulus of the studied isomers are obtained. By comparing the space groups of Pbca and Pnam in SnO2 the Vickers hardness of the two crystal structures was found to be consistent. There was a difference in the band gap between the SnO2 isomers. Energies of valence bands varied from -10 to 0 eV and -20 to -15 eV for all SnO2 crystals. These valence bands resulted from the O 2p and 2s orbitals. Optical properties of these SnO2 isomers were also calculated. The absorption spectrum of Pnam showed a strong peak in the ultraviolet range. Rules for electron transitions were determined for the different space groups of SnO2.

Key words: SnO2, Pressure, First principles, Optical property